Straight-bar knitting machine



Feb. 25, 1947. s. w. B. LACEY STRAIGHT-BAR KNITTING MACHINE Filed March 28, 1946 Jydney W3 Z0869:

BY I

ATTORNE r;

Patented Feb. 25, 1947 UNITED STATESPATENTD OFFICE Application March 28, 1946, Serial. No. 657.797 In Great Britain May 27, 1944:

6 Claims. 1

This invention relates to improvements in straight-bar knitting machines and refers to improvements in the method of operating the reciprocating parts, that is to say, the draw mechanism for such machines. In straight-bar knitting machines as normally constructed the reciprocating parts are operated by a draw lever which is oscillated'by a cam controlled slide. When wear develops in the working parts there is a tendency for the draw lever to chatter which consequently transmits an unsteady drive to the reciprocating parts. The object of the present invention is to provide a steady drive for the reciprocating parts of a straight-bar knitting machine.

According to this invention the reciprocating parts of a straight-bar knitting machine are connected to a fluid pressure operated piston disposed in a cylinder and reciprocated therein by fluid supplied under pressure to the cylinder through the necessary control valves by a pump. A pressure controlling device is provided to control the rate of flow to the cylinder so that the speed of operation 'can be varied and provision is made for the piston to stand at the end of each stroke for the knitting of the course drawn each stroke of the piston. A cut-out is also provided so that the piston and consequentlythe reciprocating parts can be put out of action during fashioning operations. 7

The invention w ll now be more particularly described with reference to the accompanying drawings in which:

Fig. 1 shows diagrammatically the method of operating the reciprocating parts. of a straightbar knitting machine by fluid supplied under pressure from a pump. 7

Fig. 2 is a sectional front elevation and Fig. 3 a sectional side elevation of part of a I straight-bar knitting machine showing one method of connecting the fluidoperated piston to the reciprocating parts.

Like letters indicate like parts throughout the drawings.

In carrying out this invention a cyl nder A and piston B (see Fig. 1) are mounted at a convenient place on the machine. The cylinder A is of suitable diameter and sufficient length to provide the necessary stroke to the piston B;

The latter is connected to the reciprocating parts in any convenient manner and for this purpose it is provided with a piston rod C which may as shown in Fig. 1 be connected directly to a slide D which is in turn connected to the-reciprocating parts of the machine or the rod C may be connected to a lever E pivoted at one end to the frame of the machine and having its other end con'nectedto the slide D by a link F as shown in Figs. 2 and 3. 'With either arrangement it will be seenthat the reciprocation of to the reciprojected to fluid pressure first on one side and then on the other. Fluid under pressure is supplied through a conduit to the cylinder A by a pump G driven in any convenient manner. The fluid drawn from the reservoir 0 passes from the pump G through a control valve H, which can be adjusted to control the rate of flow, to a valve box J containing two valves which control the passage of the fluid along conduits leading'to the respective sides of the piston B. These valves are each opened and closed by pressure provided by a secondary pressure circuit or system which is supplied from the main pump G and works in the following manner.

The two valves are controlled by pressure operated relays K, K of known construction which are disposed in the secondary pressure circuit connection with each valve and operated on a time basis to build up a predetermined pressure, the relaysjbeing provided with adjusting means to vary the time necessary to build up the pressure to that required to operate its associated valve. The supply of fluid under pressure to the relays is controlled by a switch valve L disposed in the secondary pressure circuit and operated to supply either one relay or the other to operate the appropriate valve according to the 7 the'appropr'iate relay K or K into operation at the end of each stroke of the piston B.

The secondary pressure circuit is divided into' two parts, one part supplying fluid under pressure to onegrelay K and the other part supplying fluid under pressure to the other relay K1 as 7 clearly shown in Fig. 1. The two parts of the secondary circuit are supplied with fluid under pressure through the switch valve L from the main pump G and in order to prevent excessive pressure build ng up in the secondary circuit each part thereof is provided with a pressure controlling switch or release valve M.

The arrangement works in the following m'anner. Fluid under pressure is supplied to one side of the piston through the appropriate control valve and the piston moved in its cylinder say from left to right. end of its stroke the switch valve L is operated. Assuming the piston B is at the right end of the cylinder A as shown in Fig. 1 the operation'of the switch valve L will bring the relayK con- When the piston reaches the reverse direction the switch valve L is again operated. This brings the other relay K into:

' operation which opens the other valve after the predetermined delay of time, during which knitting of the last drawn course is knitted, to move the p ston to the right and repeat the cycle of operations just described.

The'control valve I-I through which the fluid I first passes when delivered from the pump is ad-.

justable so that the rate of flow can be adjusted as desired. The speed of movement of the piston depends on the rate of flow and consequently the control valve Hgoverns the speed of movement of the piston and'is preferably connected to the speed control rod of the machine so as to be automatically adjusted with movements of the latter. The rate of flow of the fluid will also eiTect the time taken for the relays K, K to build up the pressure required to operate the valves they coni r trol so that the delay of time at each end of the stroke of the piston will automatically adjust according to the rate of,fiow of the fluid and consequently to the speed of the piston.

When fashioning takes place thedraw mechanism must be put out of action and for this purpose a main cut out N is provided. The cut out is operated when the fashioning mechanism is brought into operation so that the main and sec-, ondary pressure circuitsare cut off from the pump and the draw mechanism put'out of action, the pressure being restored when the fashioning I mechanism is put out of action and the normal knitting motions continued.

Thevalve box J, the switchvalve L, the relays K, K the-release valves and the main cut out N are all connected by means of suitable fluid return conduits to the fluid reservoir 0 so that all fluid released from the respective parts through excessive pressure or surplus to requirements may return to the reservoir.

WhatI claim as'my invention is:

3. In a straight-bar knitting machine means to drive the reciprocating parts comprising a cylinder, a piston therein, means to connect the piston to the reciprocating parts, a pump to supply fluid pressure, two fluid pressure controlled valves disposed in a main pressure circuit and opened to supply fluid under pressure from the pump to the respective sides of the piston, two

fluid pressure operated relays disposed in a sec-.

ondary pressure circuit and adapted when operated to open the respective pressure controlled valves and a switch valve adjusted by a reciprocating part of th machine to supply fluid pressure to and operate the relays successively.

4. In a straight-bar knitting machine means to drive the reciprocating parts comprising acylinder, a piston therein, means to connect the piston to the reciprocating parts, a pump to supply fluid pressure, two fluid pressure controlled valves opened to supply fluid under pressure from the pump, to the respectiv sides of the piston, means to open the pressure controlled valves at the'appropriate time to reciprocate the pistonand a main pressure control valve which can be adjustedto alter the pressure of the fluid supplied to the respective sides of the piston.

5. In a straight-bar knitting machine means to drive the reciprocating parts comprising a slide connected to the reciprocating parts, a cylinder,

a piston therein, means to connect the piston to the slide, a pump to. supply fluid pressure, two fluid pressure controlled valves disposed in a main pressure circuit andopened to supply fluid under pressure from the pump to the respective 1. In a straight-bar knitting machine means 1 to drive the reciprocating parts comprising a slide connected thereto, a lever connected to the I slide, a cylinderya piston therein connected to 3 the lever, a pump to'supply fluid pressure, two fluid pressure controlled valves opened to supply fluid under pressure from the pump to the re- I spective sides of 'thepiston and a switchvalve 1 adjusted by a reciprocating part of the machine I to supply fluid pressure to and open the pressure I controlled valves in succession to reciprocate the piston.

2. In a straight-bar 3 to drive the reciprocating parts comprising a cyllinder, piston therein, means to connect the piston to the reciprocating parts, a pump to'supply fluid pressure, two fluid pressure controlled valves opened to supply fluid under pressure from the pump to the respective sides of the piston, a

fluid pressure operated relay associated with each fluid pressure controlled valve to open the-latter and a :switch valve adjusted by a reciprocating 3 part of the machine-to supply fluid pressure to the relays successively.

knitting machine means 1 sides of the piston, two pressure operated relays disposed in a secondary, pressure circuit. and

adapted when operated to supply pressure to and open the respective pressure controlled valves, a switch valve associated with the relays, arms on the switch valve, abutmentson the slide to adjust the arms and operate the relays'successively" to reciprocate the piston, a main pressure control valve to regulate the pressure supplied to the two pressure circuits and a pressure cut out valve operated when required to put the mechanism out of action. 7

6. In a straight-bar knitting machine means to drive the reciprocating parts'comprising a cylinder, a piston therein, means to connect the piston to the reciprocating parts, a pump to sup plyfluid pressure, two fluidpres'sur'e controlled valves opened to supply fluid under pressure from the pump to the respective sides of the piston and a switch valve adjusted by a reciprocating part of the machine to supply fluid pressure to and open the pressure controlled valves in succession to reciprocate the piston. I

SYDNEY W. B. LACEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 7 Number Name I .Date 1,963,473 Richter June 19, 1934 1,984,319 Richter Dec. 11, 1934 FOREIGN PATENTS Number Country I Date 565,240 British Nov. 2, 19451 565,268 British Nov. 2,1944 600,547 German July 25, 1934' 

